The D-dimer assay

Assessment of accuracy of laboratory testing results, relative to peer group consensus values in external quality control, by bivariate z-score analysis: the example of D-Dimer

OBJECTIVES

The aim of this study is to develop a practical method for bivariate z-score analysis which can be applied to the survey of an external quality assessment programme.

METHODS

To develop the bivariate z-score analysis, the results of four surveys of the international D-Dimer external quality assessment programme of 2022 of the ECAT Foundation were used. The proposed methodology starts by identifying the bivariate outliers, using a Supervised Sequential Hotelling T2 control chart. The outlying data are removed, and all the remaining data are used to provide robust estimates of the parameters of the assumed underlying bivariate normal distribution. Based on these estimates two nested homocentric ellipses are drawn, corresponding to confidence levels of 95 and 99.7 %. The bivariate z-score plot described provides the laboratory with an indication of both systematic and random deviations from zero z-score values. The bivariate z-score analysis was examined within survey 2022-D4 across the three most frequently used methods.

RESULTS

The number of z-score pairs included varied between 830 and 857 and the number of bivariate outliers varied between 20 and 28. The correlation between the z-score pairs varied between 0.431 and 0.647. The correlation between the z-score pairs for the three most frequently used varied between 0.208 and 0.636.

CONCLUSIONS

The use of the bivariate z-score analysis is of major importance when multiple samples are distributed around in the same survey and dependency of the results is likely. Important lessons can be drawn from the shape of the ellipse with respect to random and systematic deviations, while individual laboratories have been informed about their position in the state-of-the-art distribution and whether they have to deal with systematic and/or random deviations.

An observational study investigating soluble immune checkpoints as indicators of severe COVID-19

This study aimed to investigate the immunomodulatory behavior of soluble immune checkpoints (sICPs) and other biomarkers in the pathophysiology of SARS-CoV-2 infection. The study included 59 adult participants, 43 of whom tested positive for SARS-CoV-2. Patients were divided into three cohorts: those with moderate disease (n = 16), recovered patients with severe disease (n = 13), and deceased patients with severe disease (n = 16). In addition, 16 participants were pre-pandemic subjects negative for SARS-CoV-2. The relative activity of neutralizing antibodies (rNAbs) against SARS-CoV-2 and the values of 14 sICPs in peripheral blood were compared between the four groups. Because the increase of markers values of inflammation [NLR > 12; CRP > 150 mg/L] and venous thromboembolism [D-dimer > 0.5 mg/L] has been associated with mortality from COVID-19, the total and differential leukocyte counts, the NLR, and CRP and D-dimer values were obtained in patients with severe disease. No differences in rNAbs were observed between the cohorts. Only the levels of five sICPs, sCD27, sHVEM sTIM-3, sPD-1, and sPDL-1, were significantly higher in patients with severe rather than moderate disease. The sPDL-2 level and NLR were higher in deceased patients than in recovered patients. However, there was no difference in CRP and D-dimer values between the two groups. Of the five soluble biomarkers compared among patients with severe disease, only sPDL-2 was higher in deceased patients than in recovered patients. This suggests that immuno-inhibitory sICPs might be used as indicators for severe COVID-19, with sPDL-2 used to assess individual risk for fatality.IMPORTANCECOVID-19, the disease caused by a SARS-CoV-2 infection, generates a broad spectrum of clinical symptoms, progressing to multiorgan failure in the most severe cases. As activation of the immune system is pivotal to eradicating the virus, future research should focus on identifying reliable biomarkers to efficiently predict the outcome in severe COVID-19 cases. Soluble immune checkpoints represent the function of the immune system and are easily determined in peripheral blood. This research could lead to implementing more effective severity biomarkers for COVID-19, which could increase patients' survival rate and quality of life.

Effects of dabigatran, rivaroxaban, and apixaban on fibrin network permeability, thrombin generation, and fibrinolysis

INTRODUCTION

There are important pharmacological differences between direct oral anticoagulants (DOAC) and a deeper knowledge of how they influence different aspects of hemostasis in patients on treatment is desirable.

MATERIALS AND METHODS

Blood samples from patients on dabigatran (n = 23), rivaroxaban (n = 26), or apixaban (n = 20) were analyzed with a fibrin network permeability assay, a turbidimetric clotting and lysis assay, the calibrated automated thrombogram (CAT), plasma levels of thrombin-antithrombin complex (TAT) and D-dimer, as well as DOAC concentrations, PT-INR and aPTT. As a comparison, we also analyzed samples from 27 patients on treatment with warfarin.

RESULTS

Patients on dabigatran had a more permeable fibrin network, longer lag time (CAT and turbidimetric assay), and lower levels of D-dimer in plasma, compared with patients on rivaroxaban- and apixaban treatment, and a more permeable fibrin network than patients on warfarin. Clot lysis time was slightly longer in patients on dabigatran than in patients on rivaroxaban. Warfarin patients formed a more permeable fibrin network than patients on apixaban, had longer lag time than patients on rivaroxaban (CAT assay), and lower peak thrombin and ETP compared to patients on treatment with both FXa-inhibitors.

CONCLUSIONS

Results from this study indicate dabigatran treatment is a more potent anticoagulant than apixaban and rivaroxaban. However, as these results are not supported by clinical data, they are probably more related to the assays used and highlight the difficulty of measuring and comparing the effect of anticoagulants.

Advances in D-dimer testing: progress in harmonization of clinical assays and innovative detection methods

The D-dimer is a sensitive indicator of coagulation and fibrinolysis activation, especially valuable as a biomarker of intravascular thrombosis. Measurement of plasma D-dimer levels plays a crucial role in the diagnosis and monitoring of conditions such as deep vein thrombosis, pulmonary embolism, and disseminated intravascular coagulation. A variety of immunoassays, including enzyme-linked immunosorbent assays, latex-enhanced immunoturbidimetric assays, whole-blood aggregation analysis, and immunochromatography assays, are widely used in clinical settings to determine D-dimer levels. However, the results obtained from different D-dimer assays vary significantly. These assays exhibit intra-method coefficients of variation ranging from 6.4% to 17.7%, and the measurement discrepancies among different assays can be as high as 20-fold. The accuracy and reliability of D-dimer testing cannot be guaranteed due to the lack of an internationally endorsed reference measurement system (including reference materials and reference measurement procedures), which may lead to misdiagnosis and underdiagnosis, limiting its full clinical application. In this review, we present an in-depth analysis of clinical D-dimer testing, summarizing the existing challenges, the current state of metrology, and progress towards harmonization. We also review the latest advancements in D-dimer detection techniques, which include mass spectrometry and electrochemical and optical immunoassays. By comparing the basic principles, the definition of the measurand, and analytical performance of these methods, we provide an outlook on the potential improvements in D-dimer clinical testing.

Can we predict bleeding at admission in Crimean-Congo hemorrhagic fever?

BACKGROUND

In Crimean-Congo hemorrhagic fever, bleeding has a significant impact on the prognosis of the disease. In our study, we aimed to identify independent risk factors for the development of bleeding in Crimean-Congo hemorrhagic fever and to contribute to the management of the disease.

METHODS

Cases with a definitive diagnosis of Crimean-Congo hemorrhagic fever were divided into two groups: those who developed bleeding and those who did not. Demographic, clinical and laboratory parameters were subjected to logistic regression analysis in terms of risk factors for bleeding development. Cut-off values for numerical variables were determined by receiver operating characteristics.

RESULTS

A total of 74 patients diagnosed with CCHF were included in the study. Bleeding occurred in at least one defined focus in 21 patients. In the multivariate logistic regression model, procalcitonin, days from symptom onset to admission, platelet count, and d-dimer were identified as independent risk factors for bleeding development. Procalcitonin had the most significant effect, with an approximately 5.3-fold increase in bleeding risk for each unit increase in its level. For discriminate bleeding, LDH and ferritin exhibited the highest sensitivity, while procalcitonin showed the highest specificity.

CONCLUSION

This study demonstrates the potential use of specific clinical and laboratory variables to predict bleeding development in CCHF patients. Procalcitonin elevation and the time from symptom onset to hospital admission have a significant effect in predicting bleeding.

Roles of spectral dual-layer CT, D-dimer concentration, and COVID-19 pneumonia in diagnosis of pulmonary embolism

Purpose

To demonstrate advantages of spectral dual-layer computed tomography (CT) in diagnosing pulmonary embolism (PE). To compare D-dimer values in patients with PE and concomitant COVID-19 pneumonia to those in patients without PE and COVID-19 pneumonia. To compare D-dimer values in cases of minor versus extensive PE.

Methods

A monocentric retrospective study of 1500 CT pulmonary angiographies (CTPAs). Three groups of 500 consecutive examinations: 1) using conventional multidetector CT (CTC), 2) using spectral dual-layer CT (CTS), and 3) of COVID-19 pneumonia patients using spectral dual-layer CT (COV). Only patients with known D-dimer levels were enrolled in the study.

Results

Prevalence of inconclusive PE findings differed significantly between CTS and CTC (0.8 % vs. 5.4 %, p < 0.001). In all groups, D-dimer levels were significantly higher in PE positive patients than in patients without PE (CTC, 8.04 vs. 3.05 mg/L; CTS, 6.92 vs. 2.57 mg/L; COV, 10.26 vs. 2.72 mg/L, p < 0.001). There were also statistically significant differences in D-dimer values between minor and extensive PE in the groups negative for COVID-19 (CTC, 5.16 vs. 8.98 mg/L; CTS 3.52 vs. 9.27 mg/L, p < 0.001). The lowest recorded D-dimer value for proven PE in patients with COVID-19 pneumonia was 1.19 mg/L.

Conclusion

CTPAs using spectral dual-layer CT reduce the number of inconclusive PE findings. Plasma D-dimer concentration increases with extent of PE. Cut-off value of D-dimer with 100 % sensitivity for patients with COVID-19 pneumonia could be doubled to 1.0 mg/L. This threshold would have saved 110 (22 %) examinations in our cohort.

Combining KRAS gene status with preoperative D‑dimer levels as a predictive marker of venous thromboembolism risk in patients with resectable colorectal cancer: A prospective cohort study

Colorectal cancer (CRC), one of the most prevalent types of cancer, is accompanied by a notably high incidence of thrombotic complications. The present study aimed to elucidate the association between KRAS mutations and hypercoagulability in operable CRC. The prognostic value of preoperative D-dimer levels was also investigated, thus providing novel insights into the development of therapeutic strategies to enhance patient survival and diminish morbidity. Therefore, a prospective analysis of 333 CRC cases post-surgery at Yan'an Hospital Affiliated to Kunming Medical University, between May 2019 and October 2022 was performed. Data on demographics, tumor characteristics and D-dimer levels were compiled from the electronic health records. Venous thromboembolism (VTE) was diagnosed by doppler or computed tomography angiography, with D-dimer thresholds set at 550 and 1,650 µg/l. KRAS mutations at codons 12 and 13 were assessed in a subset of 56 cases. Subsequently, the factors affecting the hypercoagulable state in these patients were prospectively analyzed, focusing on the pivotal role of KRAS. The results showed that KRAS mutations were associated with elevated preoperative D-dimer levels, with 1,076 µg/l compared with 485 µg/l in the wild-type cohort, indicative of a hypercoagulable state. Increased D-dimer levels were also associated with vascular invasion, distant metastases and a heightened risk of postoperative VTE. Furthermore, multivariate analyses identified KRAS mutations, distant metastases and vascular invasion as independent predictors of elevated D-dimer levels, with relative risk values of 2.912, 1.884 and 1.525, respectively. Conversely, sex, age, tumor location, differentiation grade, Ki67 index and tumor stage could not significantly affect D-dimer levels, thus indicating a complex interplay between tumor genetics and coagulation dysfunction in CRC. The current study suggested that the KRAS mutation status, distant metastasis and vascular invasion could be considered as independent risk factors of blood hypercoagulability in patients with CRC, potentially serving as prognostic factors for VTE risk.

The Curious Role of PAI-1 in Severe Obstructive Sleep Apnea

Plasminogen activator inhibitor-1 (PAI-1) has a significant role in fibrinolysis, atherogenesis, cellular senescence, and chronic inflammation. OSA (obstructive sleep apnea) leads to increased PAI-1 levels and the development of cardiovascular disease (CVD). The aim of this study was to determine the effects of CPAP therapy on coagulation parameters and PAI-1 in patients with severe OSA. This prospective, controlled study enrolled 57 patients who were newly diagnosed with severe OSA, 37 of whom had had good CPAP adherence after 6 months of therapy (usage of the device for at least 4 h per night), and their data were analyzed. The analysis showed a statistically significant increase in D-dimer values before CPAP therapy (415 (316.5-537.5)) vs. after therapy (499 (327-652)), p = 0.0282, and a decrease in fibrinogen values (3.665 ± 0.752 before CPAP therapy vs. 3.365 ± 0.771 after therapy, p = 0.0075)). PAI-1 concentration values before and after CPAP therapy did not differ significantly (17.35 ± 7.01 ng/mL before CPAP therapy vs. 17.42 ± 6.99 ng/mL after therapy, p = 0.9367). This study shows a tendency for fibrinolytic capacity to improve in patients with OSA after CPAP therapy, although PAI-1 levels did not differ significantly.

Absolute protein quantification based on calibrated particle counting using electrospray-differential mobility analysis

The traceability of in vitro diagnostics or drug products is based on the accurate quantification of proteins. In this study, we developed an absolute quantification approach for proteins. This method is based on calibrated particle counting using electrospray-differential mobility analysis (ES-DMA) coupled with a condensation particle counter (CPC). The absolute concentration of proteins was quantified with the observed protein particle number measured with ES-DMA-CPC, and the detection efficiency was determined by calibrators. The measurement performance and quantitative level were verified using two certificated reference materials, BSA and NIMCmAb. The linear regression fit for the detection efficiency values of three reference materials and one highly purified protein (myoglobin, BSA, NIMCmAb and fibrinogen) indicated that the detection efficiency and the particle size distribution of these proteins exhibited a linear relationship. Moreover, to explore the suitability of the detection efficiency-particle size curve for protein quantification, the concentrations of three typical proteinaceous particles, including two high molecular weight proteins (NIST reference material 8671 and D-dimer) and one protein complex (glutathione S-transferase dimer), were determined. This work suggests that this calibrated particle counting method is an efficient approach for nondestructive, rapid and accurate quantification of proteins, especially for measuring proteinaceous particles with tremendous size and without reference standards.

D-dimers in advanced liver cirrhosis: Useful biomarker or not?

In clinical practice, the d-dimer levels rule out venous thromboembolism and diagnose disseminated intravascular coagulation. d-dimers increase in both physiological and pathological conditions. Liver cirrhosis, especially in the final stages, is characterized by complex coagulation and fibrinolysis factor disorders. Multiple mechanisms tried to explain the increased d-dimer levels in patients with liver cirrhosis and ascites. The d-dimer cut-off level used to rule out venous thromboembolism in cirrhosis is higher than that used to confirm the diagnosis of VTE or DIC in noncirrhotic patients. The cut-off d-dimer level used for the prognosis of thrombotic events is not standardized in advanced liver cirrhosis. Thus, it is necessary to update the clinical guidelines regarding the usefulness of d-dimer testing in advanced liver cirrhosis and the cut-off d-dimer levels, which should vary based on the detection method.

Risk factors and incidence of central venous access device-related thrombosis in hospitalized children: a systematic review and meta-analysis

BACKGROUND

The risk factors for central venous access device-related thrombosis (CRT) in children are not fully understood. We used evidence-based medicine to find the risk factors for CRT by pooling current studies reporting risk factors of CRT, aiming to guide clinical diagnosis and treatment.

METHODS

A systematic search of PubMed, Web of Science, Embase, Cochrane Library, Scopus, CNKI, Sinomed, and Wanfang databases was conducted. RevMan 5.4 was employed for data analysis.

RESULTS

The review included 47 studies evaluating 262,587 children with CVAD placement. Qualitative synthesis and quantitative meta-analysis identified D-dimer, location of insertion, type of catheter, number of lumens, catheter indwelling time, and central line-associated bloodstream infection as the most critical risk factors for CRT. Primarily due to observational design, the quality of evidence was regarded as low certainty for these risk factors according to the GRADE approach.

CONCLUSION

Because fewer high-quality studies are available, larger sample sizes and well-designed prospective studies are still needed to clarify the risk factors affecting CRT. In the future, developing pediatric-specific CRT risk assessment tools is important. Appropriate stratified preventive strategies for CRT according to risk assessment level will help improve clinical efficiency, avoid the occurrence of CRT, and alleviate unnecessary suffering of children.

IMPACT

This is the latest systematic review of risk factors and incidence of CRT in children. A total of 47 studies involving 262,587 patients were included in our meta-analysis, according to which the pooled prevalence of CRT was 9.1%. This study identified several of the most critical risk factors affecting CRT in children, including D-dimer, insertion location, type of catheter, number of lumens, catheter indwelling time, and central line-associated bloodstream infection (CLABSI).

Elevation of D-dimer in eosinophilic gastrointestinal diseases in the absence of venous thrombosis: A case series and literature review

Introduction

Eosinophilic gastrointestinal diseases (EGIDs) are rare and heterogeneous diseases characterized by excessive eosinophilic infiltration of the digestive system. D-dimer levels and its possible association with disease course were not reported.

Case series

We reported a series of three EGID cases presenting with high levels of D-dimer. No evidence for potential venous thromboembolism was found through computed tomography pulmonary angiogram and vascular ultrasounds. Moreover, D-dimer levels decreased after short-time systemic prednisolone administration, accompanied by remission of clinical symptoms and decrease of peripheral eosinophil counts and IgE levels.

Conclusion

Elevation of D-dimer in EGID may not represent thrombotic events but is possibly associated with disease severity. More population-based studies are needed to delineate the potential relationship among D-dimer, thrombosis, and inflammation in EGID.

Cancer-Associated Stroke: Thrombosis Mechanism, Diagnosis, Outcome, and Therapeutic Strategies

Cancer can induce hypercoagulability, which may lead to stroke. This occurs when tumor cells activate platelets as part of their growth and metastasis. Tumor cells activate platelets by generating thrombin and expressing tissue factor, resulting in tumor cell-induced platelet aggregation. Histopathological studies of thrombi obtained during endovascular thrombectomy in patients with acute stroke and active cancer have shown a high proportion of platelets and thrombin. This underscores the crucial roles of platelets and thrombin in cancer-associated thrombosis. Cancer-associated stroke typically occurs in patients with active cancer and is characterized by distinctive features. These features include multiple infarctions across multiple vascular territories, markedly elevated blood D-dimer levels, and metastasis. The presence of cardiac vegetations on echocardiography is a robust indicator of cancer-associated stroke. Suspicion of cancer-associated stroke during endovascular thrombectomy arises when white thrombi are detected, particularly in patients with active cancer. Cancer-associated stroke is almost certain when histopathological examination of thrombi shows a very high platelet and a very low erythrocyte composition. Patients with cancer-associated stroke have high risks of mortality and recurrent stroke. However, limited data are available on the optimal treatment regimen for stroke prevention in these patients. Thrombosis mechanism in cancer is well understood, and distinct therapeutic targets involving thrombin and platelets have been identified. Therefore, direct thrombin inhibitors and/or antiplatelet agents may effectively prevent stroke recurrence. Additionally, this strategy has potential benefits in cancer treatment as accumulating evidence suggests that aspirin use reduces cancer progression, metastasis, and cancer-related mortality. However, clinical trials are necessary to assess the efficacy of this strategy involving the use of direct thrombin inhibitors and/or antiplatelet therapies.

Intermediate-Risk and High-Risk Pulmonary Embolism: Recognition and Management: Cardiology Clinics: Cardiac Emergencies

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. Every specialty of medical practitioner will encounter PE in their patients, and should be prepared to employ contemporary strategies for diagnosis and initial risk-stratification. Treatment of PE is based on risk-stratification, with anticoagulation for all patients, and advanced modalities including systemic thrombolysis, catheter-directed therapies, and mechanical circulatory supports utilized in a manner paralleling PE severity and clinical context.

A real-world study of different doses of rivaroxaban in patients with nonvalvular atrial fibrillation

To explore the anticoagulant effect and safety of utilizing different doses of rivaroxaban for the treatment of patients with atrial fibrillation (AF) in the real world. A retrospective case-control analysis was performed by applying the hospital database, and 3595 patients with non-valvular atrial fibrillation (NVAF) who were hospitalized and taking rivaroxaban at Wuhan Asia Heart Hospital and Wuhan Asia General Hospital from March 2018 to December 2021 were included in the study, and were divided into the rivaroxaban 10 mg and 15 mg groups according to the daily prescribed dose, of which 443 cases were in the 10 mg group and 3152 cases were in the 15 mg group. The patients were followed up regularly, and the incidence of thrombotic events, bleeding events and all-cause deaths were recorded and compared between the 2 groups, and logistic regression was applied to analyze the influencing factors for the occurrence of adverse events. Comparison of the incidence of thrombosis, bleeding and all-cause death between the 2 groups of patients showed that the 10 mg group was higher than the 15 mg group, but the difference was not statistically significant (χ2 = 0.36, 3.26, 1.99, all P > .05); the incidence of total adverse events between the 2 groups of patients was higher in the 10 mg group than in the 15 mg group, with a statistically significant difference (χ2 = 4.53, P = .033); multifactorial logistic regression results showed that age [OR (95% CI) = 1.02 (1.00-1.04)], diabetes mellitus [OR (95% CI) = 1.69 (1.09-2.62)], D-dimer level [OR (95% CI) = 1.06 (1.00-1.11)] and persistent AF [OR (95% CI) = 1.54 (1.03-2.31)] were risk factors for adverse events (P < .05). In the real world, Asian clinicians recommend rivaroxaban 10 mg once daily for NVAF patients for a variety of reasons; however, this dose is not superior or even inferior to the 15 mg group in terms of effectiveness and safety. Advanced age, elevated D-dimer levels, history of diabetes mellitus, and persistent AF are risk factors for adverse events, and the optimal dosage of rivaroxaban or optimal anticoagulation strategy for Asian patients with nonvalvular AF requires further study.

Impact of Sample Type on D-Dimer Screening

Background

The quality of laboratory test results depends on various factors, including sample type selection. Blood samples, such as whole blood, plasma and serum are commonly used for most clinical laboratory examinations. D-dimer parameters are frequently analysed in haematology laboratories and serve as biomarkers for coagulation activation and fibrinolysis. This study aimed to assess the impact of using different sample types on the quality of D-dimer test results.

Method

An observational analytical method was used. D-dimer examination was performed using the fluorescent lateral flow immunoassay method. The study sample consisted of 26 participants aged between 18 years old and 22 years old who had no blood disorders. Whole blood and ethylenediaminetetraacetic acid (EDTA) plasma samples were used for the examination of D-dimer levels.

Results

D-dimer levels in 26 participants using whole blood samples had a mean value of 0.23 mg/L (230 ng/mL), while plasma samples yielded a mean value of 0.14 mg/L (140 ng/mL). D-dimer levels obtained from whole blood samples were higher than plasma samples but remained within the normal range of 0 mg/L-0.5 mg/L (0 ng/mL-500 ng/mL).

Conclusion

The results showed that whole blood samples were more practical than plasma samples. Nevertheless, plasma samples gave results within the normal range of D-dimer values.

Fast screening using attenuated total reflectance- fourier transform infrared (ATR-FTIR) spectroscopy of patients based on D-dimer threshold value

Attenuated Total Reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy is an emerging technology in the medical field. Blood D-dimer was initially studied as a marker of the activation of coagulation and fibrinolysis. It is mainly used as a potential diagnosis screening test for pulmonary embolism or deep vein thrombosis but was recently associated with COVID-19 severity. This study aimed to evaluate the use of ATR-FTIR spectroscopy with machine learning to classify plasma D-dimer concentrations. The plasma ATR-FTIR spectra from 100 patients were studied through principal component analysis (PCA) and two supervised approaches: genetic algorithm with linear discriminant analysis (GA-LDA) and partial least squares with linear discriminant (PLS-DA). The spectra were truncated to the fingerprint region (1800-1000 cm-1). The GA-LDA method effectively classified patients according to D-dimer cutoff (≤0.5 μg/mL and >0.5 μg/mL) with 87.5 % specificity and 100 % sensitivity on the training set, and 85.7 % specificity, and 95.6 % sensitivity on the test set. Thus, we demonstrate that ATR-FTIR spectroscopy might be an important additional tool for classifying patients according to D-dimer values. ATR-FTIR spectral analyses associated with clinical evidence can contribute to a faster and more accurate medical diagnosis, reduce patient morbidity, and save resources and demand for professionals.

Fibrinogen contribution to clot strength in patients with sepsis and hematologic malignancies and thrombocytopenia-a prospective, single-center, analytical, cross-sectional study

Background

Patients with hematological malignancies (HM) frequently present thrombocytopenia and higher risk of bleeding. Although transfusion is associated with higher risk of adverse events and poor outcomes, prophylactic transfusion of platelets is a common practice to prevent hemorrhagic complications. Thromboelastometry has been considered a better predictor for bleeding than isolated platelet counts in different settings. In early stages of sepsis, hypercoagulability may occur due to higher fibrinogen levels.

Objectives

To evaluate the behavior of coagulation in patients with HM who develop sepsis and to verify whether a higher concentration of fibrinogen is associated with a proportional increase in maximum clot firmness (MCF) even in the presence of severe thrombocytopenia.

Methods

We performed a unicentric analytical cross-sectional study with 60 adult patients with HM and severe thrombocytopenia, of whom 30 had sepsis (sepsis group) and 30 had no infections (control group). Coagulation conventional tests and specific coagulation tests, including thromboelastometry, were performed. The main outcome evaluated was MCF.

Results

Higher levels of fibrinogen and MCF were found in sepsis group. Both fibrinogen and platelets contributed to MCF. The relative contribution of fibrin was significantly higher (60.5 ± 12.8% vs 43.6 ± 9.7%; P < .001) and that of platelets was significantly lower (39.5 ± 12.8% vs 56.4 ± 9.7%; P < .001) in the sepsis group compared with the control group.

Conclusion

Patients with sepsis and HM presented higher concentrations of fibrinogen than uninfected patients, resulting in greater MCF amplitudes even in the presence of thrombocytopenia.

Development and validation of a risk model for intracardiac thrombosis in patients with dilated cardiomyopathy: a retrospective study

Intracardiac thrombosis is a severe complication in patients with non-ischemic dilated cardiomyopathy. This study aims to develop and validate an individualized nomogram to evaluate the risk of intracardiac thrombosis in patients with non-ischemic dilated cardiomyopathy. This retrospective study included patients diagnosed with dilated cardiomyopathy at first admission. Clinical baseline characteristics were acquired from electronic medical record systems. Multiple methods were applied to screen the key variables and generate multiple different variable combinations. Multivariable logistic regression was used to build the models, and the optimal model was chosen by comparing the discrimination. Then we checked the performance of the model in different thrombus subgroups. Finally, the model was presented using a nomogram and evaluated from the perspectives of discrimination, calibration, and clinical usefulness. Internal validation was performed by extracting different proportions of data for Bootstrapping. Ultimately, 564 eligible patients were enrolled, 67 of whom developed an intracardiac thrombosis. Risk factors included d-dimer, white blood cell count, high-sensitivity C-reactive protein, pulse pressure, history of stroke, hematocrit, and NT-proBNP in the optimal model. The model had good discrimination and calibration, and the area under the curve (AUC) was 0.833 (0.782-0.884), and the model's performance in each subgroup was stable. Clinical decision curve analysis showed that the model had clinical application value when the high-risk threshold was between 2% and 78%. The AUC of interval validation (30% and 70% data resampling) was 0.844 (0.765-0.924) and 0.833 (0.775-0.891), respectively. This novel intracardiac thrombosis nomogram could be conveniently applied to facilitate the individual intracardiac thrombosis risk assessment in patients with non-ischemic dilated cardiomyopathy.

Comparative study of two models predicting the risk of deep vein thrombosis progression in spinal trauma patients after operation

OBJECTIVE

Patients with preoperative deep vein thrombosis (DVT) exhibit a notable incidence of postoperative deep vein thrombosis progression (DVTp), which bears a potential for silent, severe consequences. Consequently, the development of a predictive model for the risk of postoperative DVTp among spinal trauma patients is important.

METHODS

Data of 161 spinal traumatic patients with preoperative DVT, who underwent spine surgery after admission, were collected from our hospital between January 2016 and December 2022. The least absolute shrinkage and selection operator (LASSO) combined with multivariable logistic regression analysis was applied to select variables for the development of the predictive logistic regression models. One logistic regression model was formulated simply with the Caprini risk score (Model A), while the other model incorporated not only the previously screened variables but also the age variable (Model B). The model's capability was evaluated using sensitivity, specificity, positive predictive value, negative predictive value, accuracy, F1 score, and receiver operating characteristic (ROC) curve. Nomograms simplified and visually presented Model B for the clinicians and patients to understand the predictive model. The decision curve was used to analyze the clinical value of Model B.

RESULTS

A total of 161 DVT patients were enrolled in this study. Postoperative DVTp occurred in 48 spinal trauma patients, accounting for 29.81% of the total patient enrolled. Model A inadequately predicted postoperative DVTp in spinal trauma patients, with ROC AUC values of 0.595 for the training dataset and 0.593 for the test dataset. Through the application of LASSO regression and multivariable logistic regression, a screening process was conducted for seven risk factors: D-dimer, blood platelet, hyperlipidemia, blood group, preoperative anticoagulant, spinal cord injury, lower extremity varicosities. Model B demonstrated superior and consistent predictive performance, with ROC AUC values of 0.809 for the training dataset and 0.773 for the test dataset. According to the calibration curves and decision curve analysis, Model B could accurately predict the probability of postoperative DVTp after spine surgery. The nomograms enhanced the interpretability of Model B in charts and graphs.

CONCLUSIONS

In summary, we established a logistic regression model for the accurate predicting of postoperative deep vein thrombosis progression in spinal trauma patients, utilizing D-dimer, blood platelet, hyperlipidemia, blood group, preoperative anticoagulant, spinal cord injury, lower extremity varicosities, and age as predictive factors. The proposed model outperformed a logistic regression model based simply on CRS. The proposed model has the potential to aid frontline clinicians and patients in identifying and intervening in postoperative DVTp among traumatic patients undergoing spinal surgery.

Nomogram for Risk of Secondary Venous Thromboembolism in Stroke Patients: A Study Based on the MIMIC-IV Database

This study aims to identify risk factors for secondary venous thromboembolism (VTE) in stroke patients and establish a nomogram, an accurate predictor of probability of VTE occurrence during hospitalization in stroke patients. Medical Information Mart for Intensive Care IV (MIMIC-IV) database of critical care medicine was utilized to retrieve information of stroke patients admitted to the hospital between 2008 and 2019. Patients were randomly allocated into train set and test set at 7:3. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for secondary VTE in stroke patients. A predictive nomogram model was constructed, and the predictive ability of the nomogram was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). This study included 266 stroke patients, with 26 patients suffering secondary VTE after stroke. A nomogram for predicting risk of secondary VTE in stroke patients was built according to pulmonary infection, partial thromboplastin time (PTT), log-formed D-dimer, and mean corpuscular hemoglobin (MCH). Area under the curve (AUC) of the predictive model nomogram was 0.880 and 0.878 in the train and test sets, respectively. The calibration curve was near the diagonal, and DCA curve presented positive net benefit. This indicates the model's good predictive performance and clinical utility. The nomogram effectively predicts the risk probability of secondary VTE in stroke patients, aiding clinicians in early identification and personalized treatment of stroke patients at risk of developing secondary VTE.

Super Formula for Soluble C-Type Lectin-Like Receptor 2 × D-Dimer in Patients With Acute Cerebral Infarction

Acute cerebral infarction (ACI) includes atherosclerotic and cardiogenic ACI and involves a thrombotic state, requiring antithrombotic treatment. However, the thrombotic state in ACI cannot be evaluated using routine hemostatic examinations. Plasma soluble C-type lectin-like receptor 2 (sCLEC-2) and D-dimer levels were measured in patients with ACI. Plasma sCLEC-2 and D-dimer levels were significantly higher in patients with ACI than in those without it. The sCLEC-2 × D-dimer formula was significantly higher in patients with ACI than in those without it. A receiver operating characteristic curve showed a high sensitivity, area under the curve, and odds for diagnosing ACI in the sCLEC-2 × D-dimer formula. Although the sCLEC-2 and D-dimer levels were useful for the differential diagnosis between cardiogenic and atherosclerotic ACI, the sCLEC-2 × D-dimer formula was not useful. sCLEC2 and D-dimer levels are useful for the diagnosis of ACI and the sCLEC2 × D-dimer formula can enhance the diagnostic ability of ACI, and sCLEC2 and D-dimer levels may be useful for differentiating between atherosclerotic and cardioembolic ACI.

Tumor-infiltrating platelets promote the growth of lung adenocarcinoma

PURPOSE

Platelets could promote tumor growth and metastasis. However, the role of platelets in different subtypes of non-small cell lung cancer (NSCLC) and platelet infiltration in local tumor tissue remain unclear.

METHODS

Initially, platelet infiltration in lung adenocarcinoma (ADC) and lung squamous cell carcinoma (SCC) was estimated by CD41 expression using immunohistochemistry. Subsequently, co-incubation of NSCLC cell lines and platelets was performed to compare the ability of binding platelets. Subcutaneous tumor models were established to assess the ability of platelets to promote tumor growth. Then, RNA-seq data of NSCLC was used to identify differentially expressed genes and enriched pathways. Lastly, a clinical cohort comprising of ADC and SCC patients as well as meta-analysis was analyzed to compare the difference of coagulation associated clinical parameters.

RESULTS

We found high platelet infiltration in ADC, especially of advanced disease and metastases, whereas few platelets were observed in SCC. Moreover, ADC cell lines exhibited strong ability of binding platelets compared with SCC cell lines. Platelets could also promote the growth of ADC cell lines in vivo. Furthermore, coagulation cascades and fibrinogen were upregulated in ADC. And chemical inhibition of GPIIb/IIIa-fibrinogen axis reduced the binding of ADC cells and platelets. ADC patients were also in a hypercoagulable state characterized by higher d-dimer level and shorter clotting time. Finally, meta-analysis identified a higher risk of venous thromboembolism (VTE) in ADC patients and low molecular weight heparin (LMWH) treatment was effective at reducing this risk.

CONCLUSIONS

This study identified the differences of platelet infiltration and coagulation between ADC and SCC patients, which may inform the development of anticoagulation therapies for NSCLC.

Establishment and validation of a predictive model for respiratory failure within 48 h following admission in patients with sepsis: a retrospective cohort study

Objective: The objective of this study is to identify patients with sepsis who are at a high risk of respiratory failure. Methods: Data of 1,738 patients with sepsis admitted to Dongyang People's Hospital from June 2013 to May 2023 were collected, including the age at admission, blood indicators, and physiological indicators. Independent risk factors for respiratory failure during hospitalization in the modeling population were analyzed to establish a nomogram. The area under the receiver operating characteristic curve (AUC) was used to evaluate the discriminative ability, the GiViTI calibration graph was used to evaluate the calibration, and the decline curve analysis (DCA) curve was used to evaluate and predict the clinical validity. The model was compared with the Sequential Organ Failure Assessment (SOFA) score, the National Early Warning Score (NEWS) system, and the ensemble model using the validation population. Results: Ten independent risk factors for respiratory failure in patients with sepsis were included in the final logistic model. The AUC values of the prediction model in the modeling population and validation population were 0.792 and 0.807, respectively, both with good fit between the predicted possibility and the observed event. The DCA curves were far away from the two extreme curves, indicating good clinical benefits. Based on the AUC values in the validation population, this model showed higher discrimination power than the SOFA score (AUC: 0.682; p < 0.001) and NEWS (AUC: 0.520; p < 0.001), and it was comparable to the ensemble model (AUC: 0.758; p = 0.180). Conclusion: Our model had good performance in predicting the risk of respiratory failure in patients with sepsis within 48 h following admission.

MiRNAs and Their Role in Venous Thromboembolic Complications

Venous thromboembolic complications (VTCs), which include deep vein thrombosis (DVT) and pulmonary embolism (PE), have remained a pressing problem in modern clinical medicine for a long time. Despite the already wide arsenal of modern methods for diagnosing and treating this disease, VTCs rank third in the structure of causes of death among all cardiovascular diseases, behind myocardial infarction (MI) and ischemic stroke (IS). Numerous studies have confirmed the importance of understanding the molecular processes of VTCs for effective therapy and diagnosis. Significant progress has been made in VTC research in recent years, where the relative contribution of microRNAs (miRNAs) in the mechanism of thrombus formation and their consideration as therapeutic targets have been well studied. In this case, accurate, timely, and as early as possible diagnosis of VTCs is of particular importance, which will help improve both short-term and long-term prognoses of patients. This case accounts for the already well-studied circulating miRNAs as non-invasive biomarkers. This study presents currently available literature data on the role of miRNAs in VTCs, revealing their potential as therapeutic targets and diagnostic and prognostic tools for this terrible disease.

[Benefits and drawbacks of CT scan as a triple rule-out exam in acute chest pain to exclude acute coronary syndrome, pulmonary embolism and aortic dissection]

Chest pain is one of the major causes for admission in the Emergency Room in most countries and one of the principal reasons for urgent consultation with a cardiologist or a general practitioner. After clinical examination and initial biological measurements, substantial patients require further explorations. CT scan allows the search for pulmonary embolism in the early stage of pulmonary arteries iodine contrast exploration. During the same exam at the systemic arterial phase, the search for aortic dissection or coronary artery disease is possible while exploring the later contrast in the aortic artery. This triple rule-out exam allows correct diagnosis in case of acute chest pain with suspected pulmonary embolism, aortic dissection and other acute aortic syndromes or acute coronary syndrome. But X-rays are substantially increased as well as iodine contrast agent quantity while exam quality is globally decreased. Artificial intelligence may play an important role in the development of this protocol.

Crizanlizumab in sickle cell disease

Vaso-occlusion in sickle cell disease (SCD) leads to a myriad of manifestations driving morbidity and mortality in patients with SCD. Increased leucocyte adhesion and P-selectin expression on platelets and endothelial cells is an inciting event that leads to obstruction of microcirculation by adhesion with rigid sickled red blood cells. Crizanlizumab is a first-in-class monoclonal antibody that inhibits P-selectin and has been shown to decrease the frequency of vaso-occlusive pain crises in patients with SCD in clinical trials. The role of crizanlizumab in other manifestations of SCD still needs further investigation.

Role of Fibrin Monomer Complex in Coronavirus Disease 2019 for Venous Thromboembolism and the Prognosis

Objective Venous thromboembolism (VTE) is a common complication of severe coronavirus disease 2019 (COVID-19) and is associated with its prognosis. The fibrin monomer complex (FMC), a marker of thrombin generation, is reportedly useful in diagnosing acute thrombosis. To date, there has been only one report on FMC in COVID-19, and the usefulness of FMC in COVID-19 is unknown. We therefore evaluated the frequency of VTE in non-intensive-care unit COVID-19 patients in Japan and determine the clinical utility of FMC in COVID-19. Methods This was a single-center retrospective study. Laboratory test results and outcomes (thrombosis and severe progression of COVID-19) were obtained via medical record review. We assessed the relationship between FMC and VTE incidence and evaluated the association between elevated FMC levels and severe progression of COVID-19. Patients This study included 247 patients with COVID-19 who were hospitalized between December 2020 and September 2021 and had had their levels of D-dimer and FMC measured. Results Of the 247 included patients, 3 (1.2%) developed VTE. All three had elevated FMC levels on admission; however, the D-dimer level was not elevated in one case on admission. The FMC level was significantly higher in the group with severe COVID-19 progression than in the group without severe progression. A multivariate analysis showed that severe progression was associated with elevated FMC levels (odds ratio, 7.40; 95% confidence interval, 2.63-22.98; p<0.001). Conclusion FMC can be useful for diagnosing VTE in the acute phase of COVID-19. Elevated FMC was found to be associated with severity on admission and severe progression.

Unveiling the diagnostic enigma of D-dimer testing in cancer patients: Current evidence and areas of application

BACKGROUND

Cancer is a well-known risk factor for venous thromboembolism (VTE). A combined strategy of D-dimer testing and clinical pre-test probability is usually used to exclude VTE. However, its effectiveness is diminished in cancer patients due to reduced specificity, ultimately leading to a decreased clinical utility. This review article seeks to provide a comprehensive summary of how to interpret D-dimer testing in cancer patients.

METHODS

In accordance with PRISMA standards, literature pertaining to the diagnostic and prognostic significance of D-dimer testing in cancer patients was carefully chosen from reputable sources such as PubMed and the Cochrane databases.

RESULTS

D-dimers have not only a diagnostic value in ruling out VTE but can also serve as an aid for rule-in if their values exceed 10-times the upper limit of normal. This threshold allows a diagnosis of VTE in cancer patients with a positive predictive value of more than 80%. Moreover, elevated D-dimers carry important prognostic information and are associated with VTE reoccurrence. A gradual increase in risk for all-cause death suggests that VTE is also an indicator of biologically more aggressive cancer types and advanced cancer stages. Considering the lack of standardization for D-dimer assays, it is essential for clinicians to carefully consider the variations in assay performance and the specific test characteristics of their institution.

CONCLUSIONS

Standardizing D-dimer assays and developing modified pretest probability models specifically for cancer patients, along with adjusted cut-off values for D-dimer testing, could significantly enhance the accuracy and effectiveness of VTE diagnosis in this population.

Prognostic prediction of idiopathic membranous nephropathy using interpretable machine learning

BACKGROUND

Established prognostic models of idiopathic membranous nephropathy (IMN) were limited to traditional modeling methods and did not comprehensively consider clinical and pathological patient data. Based on the electronic medical record (EMR) system, machine learning (ML) was used to construct a risk prediction model for the prognosis of IMN.

METHODS

Data from 418 patients with IMN were diagnosed by renal biopsy at the Fifth Clinical Medical College of Shanxi Medical University. Fifty-nine medical features of the patients could be obtained from EMR, and prediction models were established based on five ML algorithms. The area under the curve, recall rate, accuracy, and F1 were used to evaluate and compare the performances of the models. Shapley additive explanation (SHAP) was used to explain the results of the best-performing model.

RESULTS

One hundred and seventeen patients (28.0%) with IMN experienced adverse events, 28 of them had compound outcomes (ESRD or double serum creatinine (SCr)), and 89 had relapsed. The gradient boosting machine (LightGBM) model had the best performance, with the highest AUC (0.892 ± 0.052, 95% CI 0.840-0.945), accuracy (0.909 ± 0.016), recall (0.741 ± 0.092), precision (0.906 ± 0.027), and F1 (0.905 ± 0.020). Recursive feature elimination with random forest and SHAP plots based on LightGBM showed that anti-phospholipase A2 receptor (anti-PLA2R), immunohistochemical immunoglobulin G4 (IHC IgG4), D-dimer (D-DIMER), triglyceride (TG), serum albumin (ALB), aspartate transaminase (AST), β2-microglobulin (BMG), SCr, and fasting plasma glucose (FPG) were important risk factors for the prognosis of IMN. Increased risk of adverse events in IMN patients was correlated with high anti-PLA2R and low IHC IgG4.

CONCLUSIONS

This study established a risk prediction model for the prognosis of IMN using ML based on clinical and pathological patient data. The LightGBM model may become a tool for personalized management of IMN patients.

Signal-Enhanced Immunosensor-Based MOF-Derived ZrO2 Nanomaterials as Electrochemiluminescence Emitter for D-Dimer Detection

Metal oxide nanomaterials have garnered significant attention in the field of electrochemiluminescence (ECL) sensing due to their efficient, stable, and nontoxic properties. However, the current research on metal oxide nanomaterials has primarily focused on their cathodic luminescence properties, with limited reports on their anodic ECL properties. In this study, we utilized MOF-derived ZrO2 nanomaterials as luminophores to generate stable anodic ECL signals in the presence of the coreactant tripropylamine (TPrA). Additionally, a signal-enhancing immunosensor was developed to analyze D-dimer by incorporating the coreaction accelerator Cu-doped TiO2 (TiO2-Cu). The ZrO2 synthesized by calcining UiO-67 demonstrated nontoxicity and biocompatibility, exhibiting efficient and stable ECL emission in a TPrA solution. The inclusion of TiO2-Cu as a coreaction accelerator in the immunosensor resulted in the formation of a ternary system of ZrO2/TiO2-Cu/TPrA. The Cu doping effectively narrowed the bandgap of TiO2 and enhanced its conductivity. As a substrate, TiO2-Cu reacted with more TPrA, generating sufficient free radicals to effectively enhance the ECL signal of ZrO2. In this article, a short peptide ligand, NFC (NARKFYKGC), was designed to immobilize antibodies and maintain the activity of antigen-binding sites during the construction of the immunosensor. The developed immunosensor was used for the accurate detection of D-dimers, with a wide linear range of 0.05-600 ng/mL and a low detection limit of 21 pg/mL..

Risk factors for death associated with severe influenza in children and the impact of the COVID-19 pandemic on clinical characteristics

Background

To summarize the clinical features of severe influenza in children and the high-risk factors for influenza-related deaths and to raise awareness among pediatricians.

Methods

A retrospective study of clinical manifestations, laboratory tests, and diagnosis and treatment of 243 children with severe influenza admitted to Shenzhen Children's Hospital from January 2009 to December 2022 was conducted. Univariate logistic regression analysis and Boruta analysis were also performed to identify potentially critical clinical characteristics associated with death, and clinically significant were used in further multivariate logistic regression analysis. Subject receiver operating characteristic (ROC) curves were applied to assess the efficacy of death-related independent risk factors to predict death from severe influenza.

Results

There were 169 male and 74 female patients with severe influenza, with a median age of 3 years and 2 months and 77.4% of patients under six. There were 46 cases (18.9%) in the death group. The most common pathogen was Influenza A virus (IAV) (81.5%). The most common complication in the death group was influenza-associated acute necrotizing encephalopathy (ANE [52.2%]). Severe influenza in children decreased significantly during the COVID-19 pandemic, with a median age of 5 years, a high predominance of neurological symptoms such as ANE (P = 0.001), and the most common pathogen being H3N2 (P < 0.001). D-dimer, acute respiratory distress syndrome (ARDS), and acute necrotizing encephalopathy (ANE) were significant independent risk factors for severe influenza-associated death. Furthermore, the ROC curves showed that the combined diagnosis of independent risk factors had significant early diagnostic value for severe influenza-related deaths.

Conclusion

Neurological disorders such as ANE are more significant in children with severe influenza after the COVID-19 pandemic. Influenza virus infection can cause serious multisystem complications such as ARDS and ANE, and D-dimer has predictive value for early diagnosis and determination of the prognosis of children with severe influenza.

A Nomogram-Based Model for Predicting the Risk of Severe Acute Cholangitis Occurrence

Background

Acute cholangitis is a severe inflammatory disease associated with an infection of the biliary system, which can lead to complications and adverse outcomes. The existing nomogram-based risk assessment methods largely rely on a limited set of clinical features and laboratory indicators, and are mostly constructed using univariable models, which have limitations in predicting the severity. This study aims to develop a nomogram-based model that integrates multiple variables to improve risk prediction for acute cholangitis.

Methods

Data were retrospectively collected from 152 patients with acute cholangitis who attended the People's Hospital of Jiangsu University between January 2019 and March 2022, and were graded as having mild to moderate versus severe cholangitis according to the 2018 Tokyo guidelines. Univariate and multivariate analyses were employed to discern independent risk factors associated with severe acute cholangitis, which were subsequently integrated into a nomogram model. The efficacy of the model was appraised by leveraging Receiver Operating Characteristic (ROC) curves, calibration curves, and Decision Curve Analysis (DCA).

Results

Aspartate to alanine transaminase ratio (Transaminase ratio or TR), Neutrophil-lymphocyte ratio (NLR), C-reactive protein (CRP), and D-dimer (DD) levels were independent risk factors for severe acute cholangitis. A nomogram model was constructed based on these 4 risk factors. ROC and calibration curves were well differentiated and calibrated. DCA had a high net gain in the range of 7% to 83%. The above model was tested internally. According to the nomogram model when patients using characteristic curve critical values were divided into a low-risk group and a high-risk group, the incidence in the high-risk group was significantly higher than in the low-risk group.

Conclusion

This nomogram model may provide clinicians with an effective tool to predict the potential risk of severe acute cholangitis in patients and guide informed intervention measures and treatment decisions.

A retrospective study of the clinical characteristics of 9 children with pulmonary embolism associated with Mycoplasma pneumoniae pneumonia

OBJECTIVE

The aim of this study was to analyze the clinical characteristics and treatment of children with Mycoplasma pneumoniae pneumonia (MPP) who also present with pulmonary embolism (PE).

METHODS

This retrospective analysis examined the demographic data, clinical manifestations, laboratory tests, imaging characteristics, therapy, and prognosis of nine cases of children with Mycoplasma pneumoniae pneumonia (MPP) complicated by pulmonary embolism (PE). The study focused on patients admitted to the respiratory department of Tianjin Children's Hospital between January 2018 and December 2021.

RESULTS

The age range of the patients was 3 to 8 years old, with a median age of 7.5 years. The median number of days from pulmonary infection to the diagnosis of embolism was 14 days. All patients had refractory Mycoplasma pneumoniae pneumonia (RMPP). Among them, three patients reported chest pain, one of whom had hemoptysis, while five patients had dyspnea, and six patients experienced radiating pain at unusual sites. Five out of the nine children tested positive for lupus anticoagulant (LA), five for anticardiolipin antibody (ACA), three for anti-2-glycoprotein antibody IgM, four for reduced protein S or protein C activity, and three for elevated coagulation factor VIII. Moreover, six out of the nine children tested positive for antinuclear antibodies. All the children underwent CT pulmonary angiograms, which revealed filling defects. After sequential low-molecular heparin anticoagulation with rivaroxaban, nine children in this study showed a good prognosis, with two of them receiving thrombolytic therapy for combined cardiac embolism. Follow-up at 0.5-9 months showed the gradual resolution of the emboli in all 9 children, with no thrombotic recurrences and normalized autoantibodies and thrombophilia markers.

CONCLUSIONS

The majority of cases involving Mycoplasma pneumoniae pneumonia (MPP) combined with pulmonary embolism (PE) were diagnosed with refractory MPP (RMPP). However, PE did not always occur in the advanced stages of the disease. Most patients presented with transient autoantibody positivity, abnormal coagulation, and fibrinolytic balance. With timely treatment, the prognosis of MPP combined with PE is generally good. Additionally, rivaroxaban treatment has been shown to be safe and effective.

Use of the RCOG risk assessment model and biomarkers to evaluate the risk of postpartum venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality during pregnancy and the puerperium. The vast majority of VTE occurs after childbirth. China has not yet established standard risk assessment model for postpartum venous thromboembolism (VTE), the Royal College of Obstetricians and Gynecologists (RCOG) risk assessment model (RAM) is commonly used in clinic at present. Herein, we aimed to evaluate the validity of the RCOG RAM in the Chinese population and try to formulate a local risk assessment model by combining with other biomarkers for VTE prophylaxis.

METHODS

The retrospective study was conducted from January 2019 to December 2021at Shanghai First Maternity and Infant Hospital which has approximately 30,000 births annually, and the incidence of VTE, differences between RCOG-recommended risk factors, and other biological indicators from medical records were evaluated.

RESULTS

The study included VTE (n = 146) and non-VTE(n = 413) women who examined by imaging for suspicion of postpartum VTE. There was no statistical difference in the incidence rate of postpartum VTE between the low-score group (23.8%) and the high-score group (28%) after stratification by RCOG RAM. However, we found that cesarean section (in the low-score group), white blood cell (WBC) ≥ 8.64*10^9/L (in the high-score group), low-density lipoprotein(LDL) ≥ 2.70 mmol/L, and D-dimer ≥ 3.04 mg/L (in both groups) were highly associated with postpartum VTE. Subsequently, the validity of the RCOG RAM combined with biomarkers as a model for the risk assessment of VTE was estimated and the results showed that this model has good accuracy, sensitivity, and specificity.

CONCLUSIONS

Our study indicated that the RCOG RAM was not the best strategy for predicting postpartum VTE. Combined with some biomarkers (including the value of LDL and D-Dimer, and WBC count), the RCOG RAM is more efficient when identifying high-risk groups of postpartum VTE in the Chinese population.

TRIAL REGISTRATION

This purely observational study does not require registration based on ICMJE guidelines.

Venous malformations of the lower limb with severe localized intravascular coagulopathy treated with radiofrequency ablation and resection

Diffuse venous malformations (VMs) are relatively rare, especially the lesions locting special anatomical sites, and they are prone to casuse localized intravascular coagulopathy (LIC). Diffuse VMs can also cause bleeding and life-threatening disseminated intravascular coagulopathy (DIC) from trauma, surgery, and improper treatments. Thus, the treatment of diffuse VMs with LIC is quite tough. We report of a diffuse VMs with severe LIC that was treated with the combined use of minimally invasive treatment and open surgery.

Utility of D-dimer in total joint arthroplasty

As the number of patients receiving total joint replacements continues to rise, considerable attention has been directed towards the early detection and prevention of postoperative complications. While D-dimer has long been studied as a diagnostic tool in venous thromboembolism (VTE), this assay has recently received considerable attention in the diagnosis of periprosthetic joint infection (PJI). D-dimer values are substantially elevated in the acute postoperative period after total joint arthroplasty, with levels often exceeding the standard institutional cutoff for VTE (500 µg/L). The utility of D-dimer in detecting VTE after total joint replacement is currently limited, and more research to assess its value in the setting of contemporary prophylaxis protocols is warranted. Recent literature supports D-dimer as a good to excellent biomarker for the diagnosis of chronic PJI, especially when using serum sample technique. Providers should exercise caution when interpreting D-dimer levels in patients with inflammatory and hypercoagulability disorders, as the diagnostic value is decreased. The updated 2018 Musculoskeletal Infection Society criteria, which includes D-dimer levels > 860 µg/L as a minor criterion, may be the most accurate for diagnosing chronic PJI to date. Larger prospective trials with transparent lab testing protocols are needed to establish best assay practices and optimal cutoff values for D-dimer in the diagnosis of PJI. This review summarizes the most current literature on the value of D-dimer in total joint arthroplasty and elucidates areas for future progress.

Pathophysiology, risk, diagnosis, and management of venous thrombosis in space: where are we now?

The recent incidental discovery of an asymptomatic venous thrombosis (VT) in the internal jugular vein of an astronaut on the International Space Station prompted a necessary, immediate response from the space medicine community. The European Space Agency formed a topical team to review the pathophysiology, risk and clinical presentation of venous thrombosis and the evaluation of its prevention, diagnosis, mitigation, and management strategies in spaceflight. In this article, we discuss the findings of the ESA VT Topical Team over its 2-year term, report the key gaps as we see them in the above areas which are hindering understanding VT in space. We provide research recommendations in a stepwise manner that build upon existing resources, and highlight the initial steps required to enable further evaluation of this newly identified pertinent medical risk.

Elevated plasma D-dimer levels in patients with anti-N-methyl-D-aspartate receptor encephalitis

PURPOSE

We aimed to explore the difference in coagulation function between healthy individuals and patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis and its relationship with disease severity.

METHODS

We retrospectively compared coagulation function in 161 patients with first-attack anti-NMDAR encephalitis and 178 healthy individuals. The association between D-dimer levels and disease severity was analyzed using binary logistic regression. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of D-dimer levels for the severity of anti-NMDAR encephalitis.

RESULTS

Compared to control individuals, patients with anti-NMDAR encephalitis had higher D-dimer levels (median 0.14 vs. 0.05 mg/L, p < 0.001), blood white blood cell (WBC) count (median 8.54 vs. 5.95 × 109/L, p < 0.001), and neutrophil count (median 6.14 vs. 3.1 × 109/L, p < 0.001). D-dimers (median 0.22 vs. 0.10 mg/L, p < 0.001), blood WBC count (median 9.70 vs. 7.70 × 109/L, p < 0.001), neutrophil count (median 7.50 vs. 4.80 × 109/L, p < 0.001), and C-reactive protein (median 2.61 vs. 1.50 mg/l, p = 0.017) were higher; however, eosinophils (median 0.02 vs. 0.06 × 109/L, p < 0.001), and blood calcium (median 2.26 vs. 2.31 mmol/L, p = 0.003) were lower in patients with severe forms of anti-NMDAR encephalitis than in those with mild to moderate forms, and were associated with initial modified Rankin Scale scores. Multivariate analysis showed that D-dimer levels were significantly associated with severity [odds ratio =2.631, 95% confidence interval (CI) = 1.018-6.802, p = 0.046]. The ROC curve was used to analyze the predictive value of D-dimer levels for disease severity. The area under the curve was 0.716 (95% CI = 0.64-0.80, p < 0.001), and the best cut-off value was D-dimer = 0.147 mg/L (sensitivity 0.651; specificity, 0.705).

CONCLUSION

Serum D-dimer and neutrophil levels were independent predictors of disease severity in patients with first-attack anti-NMDAR encephalitis.

D-dimer Testing in Pulmonary Embolism with a Focus on Potential Pitfalls: A Narrative Review

D-dimer is a multifaceted biomarker of concomitant activation of coagulation and fibrinolysis, which is routinely used for ruling out pulmonary embolism (PE) and/or deep vein thrombosis (DVT) combined with a clinical pretest probability assessment. The intended use of the tests depends largely on the assay used, and local guidance should be applied. D-dimer testing may suffer from diagnostic errors occurring throughout the pre-analytical, analytical, and post-analytical phases of the testing process. This review aims to provide an overview of D-dimer testing and its value in diagnosing PE and discusses the variables that may impact the quality of its laboratory assessment.

Superior Predictive Value of D-Dimer to the Padua Prediction Score for Venous Thromboembolism in Inpatients with AECOPD: A Multicenter Cohort Study

Background

The optimal tool for risk prediction of venous thromboembolism (VTE) in inpatients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is still unknown. This study aimed to evaluate whether D-dimer could predict the risk of VTE in inpatients with AECOPD compared to the Padua Prediction Score (PPS).

Methods

Inpatients with AECOPD were prospectively enrolled from seven medical centers in China between December 2018 and June 2020. On admission, D-dimer was detected, PPS was calculated for each patient, and the incidence of 2-month VTE was investigated. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of D-dimer and PPS on VTE development, and the best cut-off value for both methods was evaluated through the Youden index.

Results

Among the 4468 eligible patients with AECOPD, 90 patients (2.01%) developed VTE within 2 months after admission. The area under the receiver operating characteristic curves (AUCs) of D-dimer for predicting VTE were significantly higher than those of the PPS both in the overall cohort (0.724, 95% CI 0.672–0.776 vs 0.620, 95% CI 0.562–0.679; P<0.05) and the subgroup of patients without thromboprophylaxis (0.747, 95% CI 0.695–0.799 vs 0.640, 95% CI 0.582–0.698; P<0.05). By calculating the Youden Index, the best cut-off value of D-dimer was determined to be 0.96 mg/L with an AUC of 0.689, which was also significantly better than that of the PPS with the best cut-off value of 2 (AUC 0.581, P=0.007). After the combination of D-dimer with PPS, the AUC (0.621) failed to surpass D-dimer alone (P=0.104).

Conclusion

D-dimer has a superior predictive value for VTE over PPS in inpatients with AECOPD, which might be a better choice to guide thromboprophylaxis in inpatients with AECOPD due to its effectiveness and convenience.

Clinical Trial Registration

Chinese Clinical Trail Registry NO. ChiCTR2100044625; URL: http://www.chictr.org.cn/showproj.aspx?proj=121626.

Acute mesenteric ischemia secondary to oral contraceptive-induced portomesenteric and splenic vein thrombosis: A case report

BACKGROUND

Mesenteric ischemia represents an uncommon complication of splanchnic vein thrombosis, and it is less infrequently seen in young women using oral contraceptives. Diagnosis is often delayed in the emergency room; thus, surgical intervention may be inevitable and the absence of thrombus regression or collateral circulation may lead to further postoperative ischemia and a fatal outcome.

CASE SUMMARY

We report a 28-year-old female patient on oral contraceptives who presented with acute abdominal pain. Her physical examination findings were not consistent with her symptoms of severe pain and abdominal distention. These findings and her abnormal blood tests raised suspicion of acute mesenteric ischemia (AMI) induced by splanchnic vein thrombosis. Contrast-enhanced abdominal computed tomography revealed ischemia of the small intestine with portomesenteric and splenic vein thrombosis (PMSVT). We treated the case promptly by anticoagulation after diagnosis. We then performed delayed segmental bowel resection after thrombus regression and established collateral circulation guided by collaboration with a multidisciplinary team. The patient had an uneventful postoperative course and was discharged 14 d after surgery and took rivaroxaban orally for 6 mo. In subsequent follow-up to date, the patient has not complained of any other discomfort.

CONCLUSION

AMI induced by PMSVT should be considered in young women who are taking oral contraceptives and have acute abdominal pain. Prompt anticoagulation followed by surgery is an effective treatment strategy.

Epstein–Barr Virus and Human Herpesvirus-6 Reactivation in Acute COVID-19 Patients

Beyond their pulmonary disease, many COVID-19 patients experience a complex constellation of characteristics, including hyperinflammatory responses, autoimmune disorders, and coagulopathies. However, the pathogenesis of these aspects of COVID-19 is obscure. More than 90% of people are latently infected with the lymphotropic herpesviruses Epstein–Barr Virus (EBV) and/or Human Herpesvirus-6 (HHV-6). Some of the inflammatory features of COVID-19 resemble clinical syndromes seen during EBV and HHV-6 infection, and these latent viruses can be reactivated by inflammatory mediators. We hypothesized that EBV and HHV-6 reactivation might be a common feature of early COVID-19, particularly in patients with more inflammation. We tested for EBV and HHV-6 reactivation in 67 patients acutely hospitalized with COVID-19 using previously validated quantitative PCR assays on the plasma. In our cohort, we found that 15/67 (22.4%) patients had detectable EBV and 3/67 (4.5%) had detectable HHV-6. This frequency of activation is somewhat more than the frequency reported for some healthy cohorts, such as blood donors and other healthy control cohorts. There was no association between EBV or HHV-6 and markers indicative of more inflammatory disease. We conclude that EBV and HHV-6 activation at about day 7 of hospitalization occurred in a modest fraction of our cohort of COVID-19 patients and was not associated with high levels of inflammation. In the modest fraction of patients, EBV and HHV-6 reactivation could contribute to some features of acute disease and pre-disposition to post-acute sequelae in a subset of patients.

Analysis of the Risk Factors for Elevated D-Dimer Level After Breast Cancer Surgery: A Multicenter Study Based on Nursing Follow-Up Data

D-dimer level is often used to assess the severity of trauma as well as the risk of thrombosis. This study investigated the risk factors for high postoperative D-dimer level. This study included a total of 2706 patients undergoing breast cancer surgery to examine the associations between various clinicopathological factors and variation in D-dimer levels. After adjusting for other factors, T stage, neoadjuvant chemotherapy, blood loss, surgery type, diabetes, and elevated leukocyte and neutrophil counts were found to be significant risk factors for D-dimer variation. This study identified several factors associated with elevated D-dimer levels and consequent thrombosis after breast cancer surgery, which may aid in the development of more precise preventive measures and interventions as well as serve as a reference for future research.

Investigation of two different human d-dimer assays in the horse

Background

D-dimer has value as a marker of thrombosis in critically ill horses and can provide additional information about prognosis. However, there are currently no equine species-specific d-dimer assays available, nor has there been any formal investigation of the applicability of human d-dimer assays in horses, so it is unknown, which assay performs best in this species. The aim of this study was therefore to evaluate and compare two human d-dimer assays for their applicability in horses.

The study included four groups of horses: clinically healthy horses, horses with gastrointestinal (GI) disease and mild systemic inflammation based on low serum amyloid A (SAA) (low SAA group), horses with GI disease and strong systemic inflammation based on high SAA (high SAA group) and, horses with thrombotic GI disease caused by Strongylus vulgaris (also called non-strangulating intestinal infarction (NSII)) (NSII group). The assays evaluated were the STAGO STA-Liatest D-di + (Stago) and NycoCard™ D-dimer (NycoCard). Intra- and inter-coefficients of variation (CV) were assessed on two d-dimer concentrations, and linearity under dilution was evaluated. A group comparison was performed for both assays across the four groups of horses. A Spaghetti plot, Spearman Correlation, Passing Bablok regression and Bland–Altman plot were used to compare methods in terms of agreement.

Results

Ten horses were included in the clinically healthy group, eight in the low SAA group, eight in the high SAA group, and seven in the NSII group. For the Stago assay, intra- and inter-CVs were below the accepted level except for one inter-CV. The NycoCard assay did not meet the accepted level for any of the CVs. The linearity under dilution was acceptable for both the Stago and NycoCard. In the group comparison, both methods detected a significantly higher d-dimer concentration in the high SAA and NSII groups compared to the clinically healthy group. Method agreement showed slightly higher d-dimer concentrations with NycoCard compared to Stago. The overall agreement was stronger for the lower d-dimer concentrations.

Conclusion

Both the Stago and the NycoCard were found to be applicable for use in horses but were not directly comparable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03313-5.

Sportomics suggests that albuminuria is a sensitive biomarker of hydration in cross combat

We have been using sportomics to understand hypermetabolic stress. Cross Combat (CCombat) has recently been initiated as a high-intensity functional training method inspired by CrossFit. We used a CCombat session to induce metabolic stress and evaluated its effects on hydration and kidney function. Blood samples were collected from 16 elite-level professional male athletes engaged in training sessions over a 96-h protocol. Blood myoglobin increased by ~ 3.5-fold (119 ± 21 to 369 ± 62 nmol/L; p = .001) in response to the protocol, returning to the pre-exercise level within 48 h. Furthermore, d-dimer levels increased from 6.5 ± 0.6 to 79.4 ± 21.3 μmol/L (p < .001) in response to exercise decreasing during recovery with high variability among the studied athletes. Albuminemia and creatininemia increased ~ 10% and cystatin C increased ~ 240% (1.7 ± 0.1 to 5.7 ± 0.5 mg/L; p < .001; effect size = 2.4) in response to the protocol. We measured albuminuria (HuA) to assess kidney permeability to albumin caused by exercise. HuA increased ~ 16-fold (0.16 ± 0.03 to 2.47 ± 0.41 μmol/L; p < .001; effect size = 1.4) in response to exercise, dropping and reaching basal levels during 48 h. Here, we suggest that microalbuminuria can be used as an early, sensitive, easy, and inexpensive biomarker to evaluate hydration status changes during intensive exercise, decreasing chronic impairment in renal function.

A Cohort Study of Rivaroxaban Combined with D-Dimer Dynamic Monitoring in the Prevention of Deep Venous Thrombosis after Knee Arthroplasty

Objective

To explore the cohort study of rivaroxaban combined with D-dimer dynamic monitoring in the prevention of deep venous thrombosis (DVT) after knee arthroplasty.

Methods

Eighty-four patients with knee osteoarthritis who went through total knee arthroplasty from June 2019 to June 2021 in our hospital were arbitrarily assigned into the study group and the control group. The patients in the control group were cured with rivaroxaban anticoagulation after operation, and the study group was cured with dynamic monitoring of D-dimer on the basis of the control group. The incidence of postoperative DVT, pulmonary embolism (PE), and bleeding complications (incision ecchymosis and bleeding events) were compared. The related indexes such as drainage volume and blood transfusion volume were compared. The levels of activated partial prothrombin time (APPT), prothrombin time (PT), and D-dimer were dynamically monitored before and after operation. Visual analogue scale (VAS) was adopted to assess the degree of postoperative incision pain, the level of limb swelling before and after operation was measured, the circumference difference of affected limb was calculated, the ecchymosis area was assessed in the form of nine-palace grid, and the scores were compared.

Results

According to the comparison of VAS score, there exhibited no remarkable difference before operation and on the first day after operation, but the VAS score decreased after operation, and the VAS score of the study group on the 3rd day, 7th day, and 14th day after operation was remarkably lower compared to the control group (P < 0.05). There exhibited no remarkable difference in drainage volume (P > 0.05), but the blood transfusion volume and total blood loss in the study group were remarkably lower (P < 0.05). There exhibited no remarkable difference in the level of PT on the 3rd day before operation and on the 3rd day after operation, but on the 7th day and 14th day after operation, the level of PT in the study group was remarkably higher (P < 0.05). The level of PT in the study group was remarkably higher (P < 0.05). There exhibited no remarkable difference in the level of APPT on the 3rd day before operation and on the 3rd day after operation, but on the 7th day and 14th day after operation, the level of APPT in the study group was remarkably higher (P < 0.05). The level of APPT in the study group was remarkably higher (P < 0.05). There exhibited no remarkable difference in the level of plasma D-dimer before operation (P > 0.05). The level of plasma D-dimer in the study group was lower (P < 0.05). In terms of the postoperative ecchymosis area score, the ecchymosis area score decreased remarkably after operation. Furthermore, the ecchymosis area score of the study group was remarkably lower (P < 0.05). In terms of the swelling degree of the affected limb, there exhibited no remarkable difference in thigh circumference and calf circumference before operation (P > 0.05), but after operation, the thigh circumference difference and calf circumference difference decreased, and the thigh circumference difference and calf circumference difference in the study group were lower (P < 0.05). The incidence of DVT in the study group was 16.67%, while that in the control group was 38.10%. No PE occurred in the two groups at the early stage after operation. There were 3 cases of incision ecchymosis, 1 case of bleeding event (incision oozing) in the study group, 11 cases of incisional ecchymosis, and 2 cases of bleeding event in the control group. In 3 patients with incisional bleeding, there were no obvious abnormalities in routine blood examination and blood coagulation indexes. The patients were given wound pressure bandaging and stopped using anticoagulants and changing wound dressings every day, all of which disappeared within 5 days. The incidence of early postoperative DVT and bleeding complications in the study group was lower (P < 0.05).

Conclusion

Rivaroxaban combined with D-dimer dynamic monitoring has high clinical value in preventing DVT after knee arthroplasty and can effectively reduce the amount of blood loss during operation and the incidence of postoperative DVT, PE, and bleeding complications, which is worth popularizing to reduce the area of ecchymosis and the degree of pain after operation and shorten the recovery process.

Association of Preoperative Plasma D-Dimer and Fibrinogen and Osteosarcoma Outcome

Objective

We aimed to evaluate the utility of preoperative D-dimer and plasma fibrinogen (PF) levels as useful markers for predicting the clinical value of patients with osteosarcoma.

Methods

145 enrolled patients with osteosarcoma were studied retrospectively. We determined the critical values of D-dimer and PF by receiver operating characteristic curve analysis. Cox regression analysis was used to assess prognostic role of the D-dimer and PF levels among osteosarcoma patients.

Results

The critical values of D-dimer and PF were calculated to be 0.46 µg/mL and 3.34 mg/mL, respectively. Upregulation of D-dimer and PF showed positive correlations with a higher clinical stage, tumour metastasis and recurrence. Survival curve results confirmed that osteosarcoma patients with higher levels of D-dimer and PF predicted worse overall survival (OS) and progression-free survival (PFS). Moreover, only a high D-dimer level was associated with a shorter OS (P = 0.013) and PFS (P = 0.042) in both the univariate and multivariate analysis.

Conclusion

Elevated preoperative D-dimer levels are correlated with aggressive clinicopathological features and poor survival outcomes, which indicates that assessment of the D-dimer could be a useful prognostic marker in osteosarcoma.